How to fix Recovery is in progress in PostgreSQL

psql -U postgres -d postgres -c "SELECT pg_is_in_recovery()"

# Check if recovery is still running
ps aux | grep "startup recovering"

# Use pg_controldata to see recovery state (if available)
pg_controldata -D $PGDATA

LOG: database system was interrupted; last known up at 2024-12-28 10:15:23
LOG: database system was not properly shut down; automatic recovery in progress
LOG: redo starts at 0/...
LOG: redo done at 0/...
LOG: database system is ready to accept connections

-- Instead of:
SELECT pg_current_wal_lsn(); -- ERROR on standby

-- Use on standby:
SELECT pg_last_wal_receive_lsn(); -- Safe on standby
SELECT pg_last_wal_replay_lsn();  -- Safe on standby
SELECT pg_is_in_recovery();       -- Safe on standby

-- Safe way to check replication slots on any server:
IF NOT pg_is_in_recovery() THEN
  SELECT slot_name, database FROM pg_replication_slots;
END IF;

-- Or use the appropriate standby functions:
SELECT slot_name, database, active FROM pg_replication_slots
WHERE NOT pg_is_in_recovery() OR function_name != 'pg_wal_lsn_diff';